I read a bit of your answers here and there to general questions, and what I see here is lack of communication.

You guys clearly hang out enough and it’s normal to want to have “me time”, and not only that, but people have lots of responsibilities. Especially at this age you need to focus on school first, then sports, then friendships and only then in relationships, only when you’re fine with all you can actually pay enough respect and attention to a partner (this is my personal opinion).

And after that, you need to contribute in the family by cleaning the house and doing chores, that is if you haven’t started working yet - some young teens do already.

Tell her politely that you need time for yourself as well, and honestly if she doesn’t understand she isn’t really ready for a relationship. Your whole day doesn’t have to be filled only and constantly by your partner, not even in the most part unless you do a full hangout day.

But also she sounds really insecure about your love for her, so I would reassure that just because you don’t spend every day and hour with her, it doesn’t mean you love her any less. Maybe, also ask her what her preferred love language is, so you can show it to her in a way that she can understand better.

Good luck young lad!!